Induced pluripotent stem (iPS) cells . (a) are created by the expression of a set of key genes in cells derived from adult tissues so that these cells can differentiate into a variety of cell types. (b) require a supply of donor egg cells, such as embryonic stem cells. (c) can differentiate into a greater variety of adult tissues than embryonic stem cells. (d) are created by nuclear transplantation.

the answer is otpion c) understanding

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before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.